Washington -- An Air Force general who overturned the sexual assault conviction of a fellow fighter pilot now finds himself caught in a political cross fire that could change military justice; perhaps, some fear, for the worse.

Citing the general's actions, lawmakers including Democratic Sens. Barbara Boxer of California and Claire McCaskill of Missouri are pressuring the Pentagon to restrict commanding officers' power to dismiss court-martial convictions. The lawmakers are not, however, seeking to restrict their officers' corresponding power to press ahead with sexual assault cases that investigators may consider weak.

The result could be a further tilting of scales that some fear already may be swinging out of balance, as a military that once seemed oblivious to sexual assault now moves full force against it. At the least, what happens next will highlight the extraordinary clout that the military justice system grants commanding officers in sexual assault and other criminal cases.

Although the general's high-profile reversal of the sexual assault conviction is seizing attention, it's a step that's rarely taken.

Meanwhile, a McClatchy Newspapers review of nearly 70 military sexual assault cases, involving thousands of pages obtained under the Freedom of Information Act, found that commanding officers aggressively pursue sexual assault prosecutions, sometimes over the objections or concerns of investigators. Many acquittals have resulted.

Lawmakers, nonetheless, are mobilizing in the wake of Lt. Gen. Craig Franklin's Feb. 26 overturning of the aggravated sexual assault conviction of Lt. Col. James Wilkerson, an F-16 pilot who's back on active duty after his release from a military prison in Charleston, S.C.

"This is a travesty of justice," Boxer and Sen. Jeanne Shaheen, D-N.H., wrote Defense Secretary Chuck Hagel on March 5. "At a time when the military has unequivocally stated that there is zero tolerance for sexual assault, this is not the message it should be sending."

"This could be a tipping point, I think, for the American people to rise up, particularly the women, and say, 'I don't think one general should be able to overturn a jury,' " McCaskill told Marine Corps Gen. James Mattis, the head of the U.S. Central Command.

All of which worries military defense attorneys and scholars, who fear a congressional overreaction.

Statements 'a danger'

"The senators' ... statements are a danger to the fair administration of military justice, not just in the Wilkerson case, but in all pending and future military justice cases, especially those involving sexual assault," defense attorney Phil Cave cautioned in an interview.

A former Navy legal officer, Cave added that lawmakers' "specific interference" in the Wilkerson case amounted to an abuse of their authority and might amount to unlawful command influence. Wilkerson's civilian defense attorney, Frank Spinner, agreed in an interview Friday that "the senators' statements may constitute unlawful command influence and will have a chilling effect" on military officials.

The demands from Boxer and Shaheen that Hagel take immediate steps to restrict commanding officers from "unilaterally dismissing military court decisions" appears to conflict with the Uniform Code of Military Justice, which is written by Congress.

"It's completely inappropriate," Eugene Fidell, who teaches military law at Yale Law School, said of the senators' demands. "If they're serious about this, they should change the statute."

Boxer and Shaheen suggest that legislative changes might, in fact, be a possibility, something Fidell says could be useful if handled in a balanced fashion. He did not, however, mean the kind of bill to be introduced Wednesday by Rep. Jackie Speier, D-Calif., which would strip away a commander's ability to dismiss convictions.

Dismissals rare

The political hubbub over Franklin's actions, moreover, might create a misleading impression about the frequency with which commanding officers overturn convictions. Marine Corps Col. John Baker, the chief defense counsel of the Marine Corps, said that it was very rare for convictions to be dismissed. Fidell agreed that "it's rare, though it does happen."

The Uniform Code of Military Justice grants considerable clout to commanding officers, called in legal cases the "convening authority." The power is both at the front end, before trial, and at the back end, after trial. They may proceed with a prosecution or, as happened in the Wilkerson case, dismiss a conviction for what the uniform code specifies may be "for any or no reason." These pretrial and post-trial powers help balance each other.

"The pieces of the system have to hang together," Fidell said, adding that changing the post-trial power without addressing pretrial powers would "be a severe blow to the logic of the system."

This may be particularly true in a political climate where commanding officers feel pressure to prosecute sexual assault allegations. In the Marine Corps, for instance, tough talk by the commandant has complicated dozens of sexual assault cases, as defense attorneys repeatedly raise the claim of unlawful command influence.

The McClatchy review of previously unreported documents from 68 sexual assault cases at Georgia's Fort Benning, North Carolina's Camp Lejeune, California's Camp Pendleton and several other bases nationwide found commanding officers sometimes using their prosecutorial discretion to proceed with weak cases. In 30 of the 68 cases, the defendants were acquitted or were found guilty only of lesser charges.

In a number of the acquittals McClatchy reviewed, commanding officers had proceeded with prosecution despite explicit objections or serious questions raised by investigating officers.

The political focus on commanding officers' legal power will build Wednesday at a subcommittee hearing convened by a panel of the Senate Armed Services Committee. The chief judge advocates for all military branches have been summoned, though the hearing's tone will be set by the first panel of witnesses, a trio of veterans who say they were raped in 1987, 2000 and 2007, respectively.

The Wilkerson case isn't explicitly on the agenda, but it will be on everyone's mind.

A married, 20-year veteran of the Air Force, Wilkerson was serving as the inspector general of the 31st Fighter Wing at Aviano Air Base in Italy last March when he was accused of sexual assault. A 49-year-old physician assistant alleged that she woke up after a party at Wilkerson's house to find him fondling her breasts and digitally penetrating her. Wilkerson denied it.

A panel of officers convicted Wilkerson after a weeklong trial last November, during which the woman said she was "just numb most of the time" because of being assaulted, according to an account by the independent military publication Stars and Stripes.

"I'm not myself anymore," the woman testified, according to Stars and Stripes. "I'm different."

The trial panel sentenced Wilkerson to a year in prison and dismissal from the Air Force.

Franklin, the commander of the 3rd Air Force, then reviewed the case, including information that hadn't been presented to the trial panel, as well as letters supporting Wilkerson. A spokesman said the lieutenant general had concluded that the charges hadn't been proved beyond a reasonable doubt.

Speier, the California congresswoman, called the decision a "miscarriage of justice." Spinner, Wilkerson's attorney, called it entirely justified.

"These senators," Spinner said, "do not appear to be concerned with due process of law and the possibility that some women are making false claims against innocent men."